题目描述:
LeetCode 382. Linked List Random Node
Given a singly linked list, return a random node's value from the linked list. Each node must have the same probability of being chosen.
Follow up:
What if the linked list is extremely ...
LeetCode 382. Linked List Random Node
Given a singly linked list, return a random node's value from the linked list. Each node must have the same probability of being chosen.
Follow up:
What if the linked list is extremely ...
LeetCode 381. Insert Delete GetRandom O(1) - Duplicates allowed
Design a data structure that supports all following operations in average O(1) time.
Note: Duplicate elements are allowed.
insert(val)
: Inserts an item val to the collection.remove(val ...
LeetCode 380. Insert Delete GetRandom O(1)
Design a data structure that supports all following operations in O(1) time.
insert(val)
: Inserts an item val to the set if not already present.remove(val)
: Removes an item val ...LeetCode 378. Kth Smallest Element in a Sorted Matrix
Given a n x n matrix where each of the rows and columns are sorted in ascending order, find the kth smallest element in the matrix.
Note that it is ...
LeetCode 377. Combination Sum IV
Given an integer array with all positive numbers and no duplicates, find the number of possible combinations that add up to a positive integer target.
Example:
nums = [1, 2, 3] target = 4 The possible ...